<div class="loginForm">
    <?php echo $this->form ?>
</div>

<script type="text/javascript">
/* <![CDATA[ */
dojo.addOnLoad(function() {
    dijit.byId('submitbutton').setLabel('<img src="<?php echo $this->baseUrl() ?>/images/mini/key_enter.png" /> Entrar');
});
/* ]]> */
</script>